See http://trac.webkit.org/export/89097/trunk/LayoutTests/platform/chromium-linux/editing/selection/vertical-lr-ltr-extend-line-backward-br-expected.png Selection is off by few pixels. The complete list of vertical text tests in editing/selection: http://trac.webkit.org/changeset/89097
I think we're positioning the vertical glyphs too far to the right. We should be centered in the border: http://trac.webkit.org/export/129675/trunk/LayoutTests/platform/chromium-linux/fast/writing-mode/border-vertical-lr-expected.png The non-rotated glyphs (the numbers) seem further left: http://trac.webkit.org/export/129675/trunk/LayoutTests/platform/chromium-linux/fast/dynamic/text-combine-expected.png Maybe we're setting the origin of the glyph incorrectly?
Non-rotated glyphs look OK: http://trac.webkit.org/export/129675/trunk/LayoutTests/platform/chromium-linux/fast/writing-mode/vertical-lr-replaced-selection-expected.png
https://code.google.com/p/chromium/issues/detail?id=230590